Question 419733
(sqrt6 plus 2 sqrt3) (sqrt 6 minus 2 sqrt 3)
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The sum times the difference = diff of the squares
{{{(a+b)*(a-b) = a^2 - b^2}}}
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{{{(sqrt(6) + 2sqrt(3))*(sqrt(6) - 2sqrt(3)) = 6 - 4*3 = -6}}}